Is it possible to register with a permanent address starting 1 January. Currently I have started working full time in Italy, but staying in hotel until pre xmas before returning to the UK for Xmas, and returnig to a permanent apartment ideally from 1 Jan. Or should i start my permanent lease before 31 December?

Registration for "residenza" is independent from Brexit.

Well it isnt. YOu need to have residency before 1 Jan. So, the answer to your question is yes, get a registered contract before the end of the year and your residency at least applied for.

Thanks again for your help. i will ensure my house contract starts early or mid December as critical to get the residence applied for before the end of the year (although I understand it does not need approval before end of the year....submission is ok?)

Submission should be OK as far as dates are concerned - but you do realise that the Comune will very likely send the local police round to check that you are actually living there before granting residency (nothing personal or Brexit-related, that's the system for everybody)?

As of january 1st you will still be able to apply for residency but as a TCN and I believe the process will be much harder , if you wnat to come here as an EU Citizen it needs to be done by decmeber , and with Covid and the Holiday season you can expect the local council offices to be stretched and a lot can depend on the size of the council and the number of other applicants

Come on, not exactly a known abbreviation TCN? Third country national - I came up with American church, software and several others before finding it!

I imagine many comuni will expect British citizens to have a permesso di soggiorno from January, regardless of whether or not that's actually the law! When I was applying for residency through self-employment, the people at the comune often said to me "this would be much easier if you have a permesso di soggiorno" which actually meant "this would be much easier for me because you'd have gone through all this at the Questura".

The cost is quite high. A stay beyond 3 months is €70 and a PdiS for a year €80..
PdiS permanente are difficult to obtain if your not working.

Sorry about that , Ive spent so much time recently on related issues that is become part of my vocabulary . All Brits should be aware that unless they have residency and the WA document by 31/ 12 then that is what they will be termed .

If Boris pulls some sort of Brexit deal within the next 5weeks will rights for UK citizens be part of the agreement are we all TCN?

I doubt it, because its all part of free movement and right to stay which Pritti/Boris reckon is the basis for leaving......

Which is only fair, because we all knew what we were voting for (apart from those of us who were excluded from the vote....)

I assume any UK citizen who wants to move to Italy from January onwards will have to obtain a permesso di soggiorno now? I can't see a special case being made for new arrivals.